The park’s tan nature tour buses leave from the Wilderness Access Center throughout the day. For a good introduction, take a five-hour Denali natural history tour ($62 adults, $32 children) to Primrose Ridge (17 miles each way), or for a better look, join the seven-hour tundra wilderness tour ($104 adults, $53 children, includes a box lunch) to Toklat (53 miles each way).
Kantishna Experience is a 12-hour tour ($155 adults, $78 children, includes lunch) that focuses both on wildlife and the history of this old gold mining town. These tours are extremely popular, and they fill up fast, so you need to make your reservations (907/272-7275 or 800/622-7275, www.reservedenali.com [1]) as far in advance as possible.
Katnishna Wilderness Trails (907/683-8002 or 800/230-7275, www.denaliwildlifetour.com [2], $145) provides private all-day bus tours that leave Denali Park hotels at 6:30 a.m. These take you to Kantishna Roadhouse near the end of the road for a lunch, gold panning, and sled dog demonstration before heading back out, arriving at the hotels by 7 p.m.
Links:
[1] http://www.reservedenali.com
[2] http://www.denaliwildlifetour.com